Electric signal



(N 0 Model.)

f 2Sheets-Sheet1. H. RI MILLER. 7 Electric Signal. No. 237,575. 4 f Patented Feb. 8, I881.

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I limlh H. R. MILLER.

Electric Signal.

W I nun I.

ILFEIERS, FHOTOIJTHUBRAFNER, WASHINGTON. D (L 2 SheetsSheet 2.

Patented Feb. 8,1881.

NITED STATES PATENT FFIQEO ELECTRIC SIGNAL.

SPECIFICATION forming part of Letters Patent NO. 237,575, dated February 8, 1881.

Application filed April 6, 1880.

To all whom it may concern Be it known that I, HOMER R. MILLER, of Framingham, in the county of Middlesex and State of Massachusetts, have invented a new and useful Improvement in Electric Signals; and I do hereby declare that the following is afull, clear, and exact description of the same.

My invention relates to electric signals of that class which are adapted to be used in circuits, in any number, for giving a special signal at each particular point or station from any other point or station, at the will of the operator. It is specially designed to be used in connection with electric speaking telephones, but is also applicable forindependent use, for signaling ,to independent stations or rooms included in the same circuit.

My invention consists, first, of a primary electro-magnet, included in the main line or circuit and adapted to operate an escapement or like mechanism to release a bell-armature, in combination with a secondary electromagnet, included in a loop from the main line, connection with said loop being made and broken by the movement of the bell-hammer in striking, and of the armature to which said bellhammer is attached, whereby the operator at a distant station is able to release the bellhammer connection at any required station or point, establish communication through the loop, and sound the signal without disturbance of any other signal in the circuit.

The invention consists, further, of certain details of construction whereby the apparatusis made more simple in construction and more efficient in operation. All these matters are fully set forth hereinafter, and are illustrated in the accompanying drawings, in which- Figure 1 is a plan view of the instrument adapted to a closed circuit. Fig. 2 is a side view of the same, partly in section. Figs. 3 and 5 are detached views of the shunting devices. Fig. 4 is a diagram of a circuit including several instruments.

In the figures of the drawings, A A represent an electro-magnet located in the main circuit of the line. Fitted to this is an armature, a, maintained in proper position in relation to the magnet by light spring-supports, which are adjusted to hold the said armature, when at rest, away from the magnet.

(No model.)

In front of the armature, and mounted in standards I) b, is a rock-shaft, c, which carries an escapement, d. The shaft 0 is rocked by means of a post fixed thereon, and connected to the armature by a light bar, 6. The amount of motion imparted to the escapement by means of the armature is sufficient to cause it to move the escapement-wheel f one notch at each oscillation of the said armature.

On the shaft of the escapement-wheel is a cam or stud, g,-adapted, when the said shaft has been rotated a sufficient distance, to lift a stop-bar, h, pivoted so as to fall, when not so lifted, in rear of a second armature, "i. This second armature operates in connection with a second electro-magnet, B, which isincluded in a loop from the main wire, and is adapted to ring a bell, B, represented as mounted over the second magnet.

The apparatus may be used with an open circuit or with a closed circuit and several instruments.

In Figs. 1 and 2 is shown the apparatus adapted to the closed circuit, and for any number of instruments in the same circuit. In this form the devices for operating the bar which dogs the bell-armature have been described above, and are shown in Figs. 1 and 2.

The shunting devices are shown more clearly in Figs. 3 and 5. The magnet which operates the escapement is included in the main circuit 5 5, (shown in dotted lines.) The loop which includes the coil of the electromagnet for the bell is located at 6, the wires returning to nearly the same point, but leaving a space, (shown more clearly in Figs. 5 and 7,) which is closed by a plate or bar, 8, held in contact with the two branches of the main wire 7 7 by means of a spring, 13. When the plate is in contact at 7 7 the main circuit is closed, and the current following the line of least resistance passes through said main circuit and does not operate on the loop sufficiently to ring the bell. When, however, this bar and plate is thrown off from the points 7 7, the main direct line is interrupted and the loop is brought into the main circuit, so as to operate the bell-magnet and ring the bell. The plate or bar is operated by the spring and tail u of the hammer. The armature rocks on the spring-standards from a pivotal point, and

when drawn forward by the bell-magnet lifts or swings the tail a clear from the plate, allowing it to touch at 7 7 and complete the main circuit. This cuts out the loop and lets the armature and bell-hammer drop back, opening the main circuit and again including the loop. This action is repeated automatically as long as the lever ceases to dog the'armature.

The form of the shunting devices may be greatly varied, provided only that the retraction of the armature carrying the bell-hammer open the switch in the main circuit and include the loop.

On the end of the shaft of the eseapementwheel is an index-finger, q, moving over the face of a numbered dial, a. The index-finger moves with the shaft, and may be set for any number. Obviously, the index-finger may be turned on the shaft to any number, and when pointing to that number on the dial the cam is to be in proper position to lift the stop-lever, as explained. \Vhere there are several instruments in the same circuit these indexes are to be set on each machine for its appropriate number, and the operation at any station or point desiring to signal any other specified station makes and breaks the connection until the inden-finger of the dial of his own instrument points to the number of the specified station, and then the lug on the shaft of the escapement-wheel of that particular instrument will have lifted the stop-lever and released the armature of the bell-magnet.

The apparatus may be operated either by a battery or by a magnetoelectrical machine.

Other devices may be used instead of the eseapement, though I consider the mechanism shown simple and convenient.

Manifestly, the shunting devices may be in- 40 definitely changed.

It should be noted that the device for lifting the stop-bar which dogs the armature of the bell should be so made as to operate on said bar quickly, since all the instruments in the circuit will move simultaneously, and at those set for lower numbers. when the higher are called, the bar will be lifted only for an instant. In that case only a single stroke, at most, can be sounded.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. An electric signal consisting of an electro-magnet situated in the main line or circuit, and adapted to operate mechanism to dog or release the armature of a second electro-magnet, in combination with such second magnet, situated in a loop of the said main circuit, and also in combination with shunting devices in said loop, operated by the motion of the bellhammer or armature, whereby any given bell may be rung continuously, at pleasure, as set forth.

2. In an electric signal, the combination of 65 the electro-magnetA A, its armature connected to the eseapement, and the escapement-wheel, with the cam or lug on the shaft of said wheel, and the bell-armature of the electro-magnet included in the loop, as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HOMER 1t. MILLER.

Witnesses F. L. MIDDLE'roN, O. N. ATWOOD. 

